The Makhteshim phenomenon The Negev, Israel's southern half, is a colorful rocky desert, and its center is dominated by northeastsouthwest anticlinal ridges. The crests of four of these ridges host five deep, breathtaking valleys, that have in common unique features: they are surrounded by steep walls, built of hard limestone and dolomite at the upper half and friable sandstone at the bottom. Each of these valleys is drained by a single narrow river bed. Such a unique closed valley is called makhtesh (plural makhteshim), the Hebrew word for mortar. The term crater describes the rather common feature of a valley at the top of a volcano, but the steep valleys of the Negev are different - they were carved by erosion. The term makhtesh has been adopted internationally, and the geological dictionaries reher to the Negev examples.
Valleys eroded into mountainous ridges are found elsewhere, but they are irregular, cut by faults, open to various directions, and covered by soil and vegetation. In contrast, the makhteshim are deep closed valleys, bare of soil and vegetation, and the rocks are displayed in a feast of colors. The five makhteshim are geological windows, peeping into the Earth's crust and each exposing a different geological display.
The makhtesim are unique assets of nature, the only complete exemplars of their kind in the world. The rock strata are inclined, disclosing the anticlinal structure of the hosting ridges, and the visitors driving or walking through the up to 220 million years old pages of the most vivid geology books exhibited by nature.
These formations are geographically well defined shelters in which the original flora and fauna of the Negev Highland are best preserved.
Makhtesh Ramon is an awesome 38 km long, 6 km wide and 450 meters deep. Recent triassic rocks are well exposed, rich in fossils and intruded by hundreds of igneous dykes, many sills, a plutonic stock and a laccolith. The southwest part of Makhtesh Ramon is dotted with well preserved 110 million year old volcanoes, diaterms and flows of basanite, a rare kind of basalt, originating from the upper mantle. "The Carpentry" is a popular name given to six hills in Makhtesh Ramon that exhibit prisms made of quartzite, a rare feature world-wide and the target of intense research.
The inner area is dotted with archaeological remains of nomads, but in the outer area flourished Nabatean, Roman and Byzantine settlements, that lived from trade routes and supported a unique type of desert agriculture.
Hundreds of scientific papers have been published on the stratigraphy, petrology, mineralogy, fossils, tectonics, volcanology and morphology of the makhteshim. Included in Makhteshim Country are the Ramon Science Center, the Desert Research Institute, and Ben Gurion University of the Negev.